Science lesson plan · 6th grade (Year 7 in England) · 45 minutes
Continuous and discontinuous variation
Cells, genetics and evolution
CCSS NGSS.MS-LS3-2CCSS NGSS.SEP 4England: KS3 Biology: Inheritance, chromosomes, DNA and genes
Objective and success criteria
Students will: Continuous and discontinuous variation.
- I can answer questions on today's skill on my own, without help.
- I can explain each step and say why it works.
- I can check my answer and spot a mistake.
Before and after
Needs first: Inherited and environmental characteristics
Leads to: Use twins and clones to separate genes from environment
Materials: Microscope images or slides, Cell diagrams, Mini whiteboards, A diagram or short video clip of the idea, Printed student sheet (below).
Warm-up · 5 min
- Quick retrieval from earlier learning (Inherited and environmental characteristics). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- Is this characteristic inherited or environmental: a suntan? (inherited (from parents) / environmental (from life)) → environmental (from life)Prompt: Were you born with it, or did it happen during life?
- Which characteristic depends on both genes and environment? (blood group / height / natural eye colour / a tattoo) → heightPrompt: Food and health also affect this one.
- Inheritance: which statement is true? (Offspring of plants and animals usually vary from their parents. / If a parent loses a finger, its babies are born without that finger. / Children are always exact copies of one parent. / The language you speak is inherited.) → Offspring of plants and animals usually vary from their parents.Prompt: Which things can be passed on in genes?
Hook · 5 min
- Show a microscope image of cells and ask what students think they are looking at.
- Share the objective: Continuous and discontinuous variation. Read the success criteria together.
I do: model it · 10 min
- Work through the example out loud, saying why you do each step, not just what you do.
- Example: Is this continuous or discontinuous variation: height?
- Step 1: Continuous variation can take any value in a range, so it is measured.
- Step 2: So the answer is: continuous
- Answer: continuous
- Pause after each step and ask a student to say what comes next.
We do: guided practice · 10 min
- Do these together. Students try each step on whiteboards before you reveal it.
- Use the hints as prompts rather than giving the answer.
- Is this continuous or discontinuous variation: Rhesus blood type (positive or negative)? (continuous / discontinuous) → discontinuousPrompt: Can it have any value, or only a few set categories?
- Five students measured their heights in cm: 158, 175, 179, 165, 141. What is the range of their heights, in cm? → 38 cmPrompt: The range shows how spread out the data are.
You do: independent practice · 10 min
- Students work on the student sheet. Circulate and check the first two answers of every student early.
- Students who finish: write a question of their own for a partner, with the answer.
The 8 questions are on the student sheet below, with answers in the key.
Exit ticket · 5 min
- Two questions on their own. Sort answers into got it / nearly / not yet to plan the next lesson.
- Is this continuous or discontinuous variation: ABO blood group? (continuous / discontinuous) → discontinuousPrompt: Can it have any value, or only a few set categories?
- Height data for a large group of adults usually form which shape when plotted? (two separate bars / a bell-shaped curve (normal distribution) / a flat line / a straight rising line) → a bell-shaped curve (normal distribution)Prompt: Most people are near the middle; few are very tall or very short.
Watch out for
- Everyday meanings of words getting in the way of the science meaning: define key words explicitly.
- Remembering facts without the reason: ask "why?" and "what is the evidence?"
Support and stretch
Support
- Review first: Inherited and environmental characteristics.
- Use concrete materials: microscope images or slides.
- Give the first step of each question, or a partly worked example to finish.
- Pair with a confident partner for the guided practice.
Stretch
- Move on to: Use twins and clones to separate genes from environment.
- Explain a common mistake in writing and how to fix it.
- Write a word problem that uses today's skill, then solve a partner's.
Homework and more practice
Free online practice with hints and printable worksheets for this skill: eurekami.com/science/grade-6.
Free lesson plan from eurekami.com/lesson-plan-builder